1. Field of the Invention
The invention relates to a casing, more particularly to a computer casing provided with an elongated spring plate for resiliently retaining a casing cover thereon.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional computer casing 2 is shown to include a rectangular hollow main body 23 and a casing cover 22 disposed on the main body 23. The main body 23 has a side wall 230 formed with a fixed frame plate 21 that is parallel to and spaced apart from the side wall 230 and that is proximate to a rear end of the main body 23. The frame plate 21 has an inner surface 215, an outer surface 216, a plurality of tongue-retaining holes 212 formed through the frame plate 21, and a stop member 25 that is fixed on the outer surface 216 of the frame plate 21 near the tongue-retaining holes 212 and that is shaped as a shoulder. The casing cover 22 is sleeved slidably on the main body 23, and has an integral cover plate 220 disposed slidably on the frame plate 21 in such a manner that the cover plate 220 abuts against the stop member 25 so as to prevent the same from further sliding forward, thereby permitting rearward sliding movement of the cover plate 220 on the frame plate 21 for removal of the casing cover 22 from the main body 23. A spring unit 3 is disposed on the frame plate 21, and includes an elongated coupling section 33 sleeved on a peripheral edge of the frame plate 21, and a plurality of curved upper biasing sections 311 (only one is visible in FIG. 2) disposed above the upper surface of the frame plate 21 and extending forwardly from the coupling section 33 to bias the cover plate 220 away from the frame plate 21 in a direction that is perpendicular to the frame plate 21, thereby fixing the cover plate 220 relative to the frame plate 21. The spring unit 3 further includes a plurality of pressed lower engaging tongues 321 (only one is visible in FIG. 2) connected integrally to the coupling section 33 and projecting respectively into the tongue-retaining holes 212 in the frame plate 21, thereby preventing untimely disengagement of the spring unit 3 from the frame plate 21.
A drawback of the aforesaid conventional computer casing is that it is inconvenient to mount the spring unit 3 on the frame plate 21 in view of the fact that inner ends 322 (see FIG. 2) of the lower engaging tongues 321 have to be manually operated so as to be retained in the tongue-retaining holes 212 in the frame plate 21. Removal of the spring unit 3 from the frame plate 21 is consequently difficult.
Furthermore, the spring unit 3 easily breaks at positions 323 (see FIG. 2), thereby resulting in separation of the lower engaging tongues 321 from the remaining portion of the spring unit 3.